Question

выручайте (a-1)^2-(a+1)(a-2)

Answer 1

(a-1)$^{2}$-a$^{2}$-2a+a-2=(a-1)(a-1)-a$^{2}$-a-2=a$^{2}$-2a+1-a$^{2}$-a-2=1-3a-2=-1-3a